A remote monitoring system is a system collecting meter-reading values such as gas, water, and electricity, and security information (such as various alarms) in a remote site from a center device and is widely spread throughout the world as one of applications of Machine to Machine communication.
FIG. 17 illustrates a configuration example of a sensor network system in the related art.
In FIG. 17, meters with a communication function such as a gas meter 11 and a water meter 12 are connected to a Network Control Unit (hereinafter, referred to as a “NCU”) 10 through a 5-bit interface or an 8-bit interface which is a standard interface of the High Pressure Gas Safety Institute of Japan (KHK). The NCU 10 is connected to a center device 14 through a protector 15 and a telephone line 13, and is adapted to perform two-way communication with the center device 14. Instead of the telephone line 13, a public line such as, for example, an Integrated Services Digital Network, an Asymmetric Digital Subscriber Line, an optical line, a mobile telephone line, and a personal handy-phone system line may be used. The reason that the NCU 10 corresponds to such a wide variety of public lines is that the public lines continue to change to this day due to development of communication technology and a change in market needs, and the remote monitoring system is a system having high achievement which has been continuously used from the past.
Further, a system which is excellent in workability in a wired and wireless manner by using a local terminal network made of a host device and a plurality of the slave devices using a wireless host device and wireless slave devices is proposed (for example, see Patent Document 1).
Further, when the NCU is provided near the meter, securing a commercial power supply is difficult, and thus the NCU is likely to be driven by a battery. Since the communication frequency of the NCU is as low as several times a month, the NCU is caused to be in a sleep state except when communication is performed, and thus the same battery life as that of a test completion period of the meter may be realized.
Meanwhile, for example, in a system described in Patent Document 2, a sensor network is made using sensor terminals including various sensors of temperature, humidity, intensity of illumination, air pressure, vibration and the like which are equipped with communication functions. Sensor devices in the sensor network calculate specific indicators for realizing energy saving by analyzing a behavior pattern of a user from environmental data indicating surrounding environment and states of things, subject data indicating a condition and a behavior of a user, and energy consumption data. The sensor terminal includes devices connected to a wired network such as a LAN, and devices connected to a wireless network such as ZigBee (registered trademark), Bluetooth (registered trademark), and a specified low-power radio.    Patent Document 1: Japanese Unexamined Patent Application Publication No. H06-85938    Patent Document 2: Japanese Unexamined Patent Application Publication No. 2010-262510